walker



(No Model.) 2 Sheets-Sheet 1.

O. S. WALKER.

TWIST DRILL GRINDING MACHINE. Y No. "425,839. PatentedApr. 15, 1890.

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O. S. WALKER. TWIST DRILL GRINDING MACHINE.

Patented Apr. 15, 1890.

S I t 4 INVENTOR @a/zfW Zm UNITED STATES PATENT OFFICE.

OAKLEY S. WALKER, OF YVORCESTER, MASSACHUSETTS, ASSIGNOR TO THE \VOROESTER POLYTEOl-INIC INSTITUTE, OF SAME PLACE.

TWlST-DRlLL-GRINDING MACHINE.

SPECIFICATION forming part of Letters Patent No. 425,839., dated April 15, 1890,

Application filed October 3, 1839. Serial No. 325,948. (No model.)

To all? whom it may concern: the drill between the jaws of a peculiar- B e 1t known that I, OAKLEY S. WALKER, shaped gage attached to the drill-holder, thus a citizen of the United States, residing at making each drill adjust the machine accord- \Vorcester, in the county of W'orcester and ing to its diameter. Otherimprovements ac- 55 State of Massachusetts, have invented certain complished in my improved drill-grinding new and useful Improvements in Twist-Drillmachine are: a combination with the drill- Grinding Machines, of which the following is holder of a convenient truing device to maina Spec fication. tain the truth of the grinding-wheel, an ad- My invention relates to drill-grinding majustable stop to limit the oscillating move- 60 IO chines, but more particularly to that class ment of the drill in grinding, and an imcalled twist-drill grinders, the object being proved device to provide for the holding and to simplify their operation and to produce accurate grinding of drills constructed with improved results. two or more cutting-lips, including flat drills To these ends my invention consists of the and drills with either straight or spiral 65 construction and arrangement of the novel grooves- These various improvements Iwill mechanism hereinafter fully described. now proceed to explain with the aid of the In grinding a drill the usual method emaccompanying drawings, in which like letters ployed in presenting it to the grinding-wheel of reference indicate the same parts in each. is the swinging method, Where the drill is Figure 1 is a part section and elevation of 70 held in a drill-holder which is arranged to the drill-grinding machine witha small drill swing upon an axis, the said axis not being in place, showing the method of setting the colncident with the center line of the drill as drill-holder by means of a graduated scale, the 1t lies in the holder. The drills are held so graduated scale being disclaimed in this apthat the ends to be ground all extend beyond plication. Fig. 2 is an elevation of the same 7 5 this axis toward the grinding-wheel, the style of drill-holder, and with the emeryground surface obtained being a curved surwheel is shown detached from the machine face with the said axis for a center, and the raand shows a larger drill in place. Fig. 3 is dins of the curve always depending upon the an elevation of the drill-holder, showing the distance of the end of the drill from said axis, operation of my new adj listing-gage. Fig. 4 8o which is obvious. It is also obvious that is an elevation similar to Fig. 3. Figs. 5 and drills of differing diameters cannot well be 6 are plan views of the drill-holder, showing ground to curves of the same radius. It folthe adj usting-gage more clearly. Fig. 7 is a lows then that a machine to grind drills propdiagram explaining the principle of the aderly should have some means of measuring justing-gage. 'Fig. 8 is an elevation of the 85 3 5 the adjustment of the drill-holder away from drill-grinding machine, illustrating the operthe axis corresponding to the size of the drill ation of the truing device. Fig. 9 is an eleto be ground. A graduated scale with a vation of a portion of the drill-holder drawn pointer arranged to move along the same has apart to illustrate the action of the adjustbeen employed to accomplish these ends. able stop. Fig. 10 is an end view of the drill- 9o This system is faulty,inasmuch as it requires holder, showing an ordinary two-lippedtwistthe machine operator to determine the size drill in place. Fig. 11 is a similar view showof each drill before grinding, which is very ing a three-lipped drill in place. Fig. 12 is often difficult to accomplish, as many drills an end view of the drill-holder and shows the are not marked and would require measurmethod of holding afour-lipped drill in the 5 ing in order to determine their sizes. V-shaped holder by means of an adjustable In my invention I obtain the proper adlateral support. Fig. 13 is a view similar to justment of the drill-holder by means of an the three preceding and shows the method of improved device, which performs the operaholding a flat drill in place. tion of simultaneously calipering a drill and Ais the main standard of the machine, and 100 giving the drill-holder the proper adjustment a the grinding-wheel. The parts B, D, and for the same. I accomplish this by placing C, with their attachments, constitute the drillholder, which is held in place in the main standard A by means of the clamping-screw A, which compresses a split hub on the standard and binds the sleeve portion 13 of the drill-holder to any part of its length, so that its longitudinal position may be rapidly adjusted.

B is a collar fastened to the sleeve B by the set-screw b, and may be adjusted at pleasme.

13 is a ball-handle attached to the inclined head, which forms one end of the-sleeve B. This inclined head is bored for the reception of a shaft forming a part of the oscillating bracket 0. The center of this shaft is represented by the axial line m y. This shaft extends below the bottom of the inclined head, and uponv the end thus protruding is mounted a collar 0, adjustably fastened by aset-screw c and having an upward-projectingfinger 0 attached to its periphery, and which extends above sufliciently to come in Contact with another projection 1) upon the inclined head of the sleeve B when the collar is made to rotate with the oscillating bracket G. Another projection 0 upon the oscillating bracket 0 similarly comes in contactwith a second projection b upon the top of the inclined head. These projections c and b form a positive stop to limit the oscil-' lating movement of the 'bracket 0 in'the direction to the left, while the movement to the right, being limited by the adjustable projection c ,-permits an adjustable limitation of the oscillating movement toward the right hand, which is a necessary requirement in grinding drills of more than two cutting-lips.

Upon the top of the oscillating bracket 0 is mounted the drill-holder top D, adj ustably fastened by the clamping-screw D and arranged to be adjusted to and from the emerywheel when the screw D is loosened.

D isa longitudinally-adjustable support for the shank of thedrill held by screw D working through a slot in the drill-holder top D.

E is the drill-stop, similarly adjusted and fastened by screw E e, E, and eare adjustable portions of the drill-stop E. The sleeve E passes through a split hub at the top of the mainsupport. of the drill-stop E and is adj ustably clamped by means of the screwe The spindle e has a longitudinal movement in the sleeve E and isoperated against the end of the drill by means of the thumb-screw e for the purpose of feeding the drill against the grindingwheel.

The end of the drill-holder top D toward the grinding-wheel is provided with a lateral projection through which is bored a hole for the reception of the wheel-truing device f, adjustably held in place by the set-screw f This truing device may be an ordinary diamond set in a cylindrical holder, or any other instrument suitable for truing emery-wheels.

The dotted lines in Fig. 8' show another position assumed by the drill-holder inpassing across the emery-wheel while truing the same,

from the axial line as 'y, and the said figures also show the method of adjusting the drillholder top by the graduated-scale system. Fig. 3 shows the sameadjustment as in Fig.

.1, but is accomplished by means of my new Fig. 4 shows the same ad adj listing-gage. justment as in Fig. 2, also by means of the adjusting-gage. D and C are the jaws of the adj usting-gage, and are more fully understood by referring to Figs. 5 and 6.

D is attached to and forms a part of the drill-holder top I), and C is attached to the oscillating bracket 0, and is therefore stationary, whileD is moved along with the drillholder top in adjusting the same for a drill. The edges of drill contact of these gage-jaws in this case are approximately parallel, and their angularity'with the line of movement of the drill-holder top depends upon the requirements of the machine.

The drill-holder top D, it will be seen, does not move at right angles to the axialline of oscillation a; g. It follows, then, that in order to move the end of the drill a certain distance beyond the axis the drill-holder top must be moved a still greater distance. It is possible, however, to change the direction of 'the adjustment, so that it shall be at right angles or at other angles with the axial line w y, in which case a modification of the adj ust ing-gage above shown would be necessary, as will be shown farther on.

It having been determined by the construction of the machine that the drill-holder top needs to be moved along its line of move ment three inches when the drill to be ground is two inches in diameter, it is obvious that the ratio of adjustment to the diameter of the drill is as three is to two. sition as a starting-point, the explanation of the diagram shown in Fig. 7 is as follows: The line 0 0 represents the edge of drillcontact of the gage-jaw C and must be conceived as stationary. The line N N and the dotted line M M represent different posi tions of the edge of drill-contact of the gagejaw D as it is adjusted in the direction 0 M corresponding to the line of movement of the drill-holder top. Conceiving the lines N N and O O to be in contact at the start, an adjustment of the distance from O to N-say one and one-half inch-will bring the lines 0' O and N N a certain distance apart measured by the perpendicular line 0 L, the length of which must beone inch, because as one and one-half is to one so is three to two, according to the proposition above mentioned. If, now, theline N N is again adjusted a distance N M equal to O N, it is obvious that the distance N L will be equal to the distance 0 L, and the drill calipered by the lines M M and O 0 will be two inches in diameter, or twice the distance 0 L, while the distance 0 M (corresponding to the whole adjustment of the drillholder) will be twice the distance 0 N, or three inches, which conforms to the ratio assumed. It is obvious that any drill calipered by the gage-jaws will adjust the drill-holder top in the same ratioas above demonstrated. It is also obvious that any difference in the angle of the lines 0 O and N N with the line of adjustment 0 M would change the ratio of the adjustment to the diameter of the drill, and if the said lines 0' O and N N were at right angles to the line of adjustment 0 M the ratio would be unity and the adjustment would equal the diameter of the drill. If the lines of drill-contact of the gage-jaws D and C (represented by the lines 0' O and N N of the diagram, Fig. 7) were other than parallelfor instance, inclined toward each other-the required result could be obtained, but the drill would have a third point of contact-"5.6., against the side of the drill-holder top-and the drill would have to be withdrawn longitudinally. In a drill grinder where the adjustment of the drill-holder top is at or near a right angle to the axial line of oscillation, the adjustment might be less than the diameter of thedrill, in which case the edges of the gage-jaws should diverge and form a V when closed together. I do not therefore confine myself to any particular ratio of adjustment of drill-holder, nor to a particular angle of gage-jaw.

In Fig. 10 at T' is shown an ordinary twistdrill, held in correct position by the lip-rest t', fastenedto the V-shaped holder by the screws 8. The lip-rest 71 is disclaimed in this application.

In Figs. 12 and 13 are shown the functions of the adjustable lateral support I for holding four lipped drills and flat drills in a V-shaped holder. I is a thin piece of steel plate working through a slit in the side of the drill-holder top D, and may be placed flush with the inner surface of the holder, as in Fig. 10, or, as in Fig. 12, moved up to support the drill upon one side, the device being held in place in each position by the set-screw J. .(Shown in Fig. (5.) In Fig. 13 the supportis placed on the opposite side of the drill from the position shown in Fig. 12. By reference to Figs. 11 and 12 it will be seen that unless the oscillating movement of the drill-holder top and the drill is limited the drill-lips T and T would come in contact with the grinding-wheel when swung far enough in that direction. The adjustable stop 0 previously explained, is designed to obviate this difficulty.

The operation of my improved drill-grinder is as follows: The clamping-screw A; is first loosened and the drill-holder is drawn out at a distance away from the grinding-wheel. The clamping-screw D is then loosened and the drill-holder top moved until the drill to be ground will pass between the jaws C and D of the adj usting-gage. The drill-holder top is thus properly adjusted for the diameter of the drill, and is then rigidly clamped to the oscillating bracket 0 by the screw D The drill is then placed in the V-shaped supports of the drill-holder, with the lip to be ground extending slightly beyond the lip-rest 2', with the edge of the groove of the drill resting against it. The drill-stop E is then moved up against the sh an k end of the drill and clamped by means of the screw E The clampingscrew A is now loosened and the whole drillholding device is moved up until the point of the drill nearly comes in contact with the grinding-wheel. Then the clamping-screw A is tightened. The drill is now held in position with one hand, while with the other the drill is fed to the grinding-wheel by means of the thumb-screw e acting against the end of the spindle e, and the drill-holder top D and guide-bracket O are at the same time oscillated to the right and left against the stops, as previously explained. The oscillating portion of the drill-holder works about the axial line 00 g, which movement may be in a helical direction toward the grinding-wheel to give the proper clearance to the drill, or the drill may be so held (by the construction of the machine) that its center line prolonged would never meet the axial line of oscillation. Thus, a ground surface being obtained eccentric with the drill, the necessary backing off (or clearance) would be obtained. These and various other methods of obtaining clearance having been previously covered, they are disclaimed in this application.

To true up the grinding-wheel, the truing device f is adjusted at a suitable distance beyond the end of the drill-holder, and is fastened by means of the set-screwy. The drill-holder is now moved up until the truing device will touch the lowest surface of the wheel. Then the collar B is fastened in contact with the hub of the main support A by means of the set-screw b.

The clamping-screw A, being left loose with one hand grasping the ball-handle B and with the other holding the oscillating portion of the drill-holder against the stop 011 the left hand, the whole drill-holder is swung about the center of the sleeve B, the collar B keeping the sleeve in place by its continuous cont-act with the casting A. The truing device f thus passes across the grindingwheel in a plane, and by its cutting action accurately trues the surface of the wheel. WVhen not in use the truing device is pushed back and fastened out of the way by the setscrew f as shown in Figs. 3 and t.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is as follows:

1. The combination, with a twist-drill-grinding machine, of. the drill-holder top D and the oscillating bracket 0, provided, respectively,.with the projecting gage-jaws D and 0, arranged to simultaneously caliper the drill 'to be ground and to axially adjust the drill-holder, as aboveset forth.

2. In a twist-drill-grinding machine, thecombination, with a V-grooved drill-holder,

of the parallel gage-jaws D and Cf Whose contactfaces are inclined to'the line of their adjustment, for the purpose above described.

3. The combination, with the drill-holder top D and oscillating bracket 0, of the adjustable stop 0 arranged to limit the oscil- Iat-ing movement of the drill-holder, as and for the purpose set forth.

4. The drill-holder top D and the oscillating bracket 0, mounted upon the sleeve B, .1 combined with the adjustable collar B and the emery-wheel truing-tool f, for the purpose described.

5. The combination of the main supportingstandard A with the emery-Wheel truing-tool f, suitably mounted upon and swingingwith the sleeve 13, for the purpose set forth.

6. The combination, with the drill-holder top Djmounted upon the oscillating'bracket C, of the adjustable stop 0 and the lateral drill-support I, arranged as and for the purpose above described.

f 7. An oscillating drill-holder provided with a lip-rest '5, combined with the adjusting gage- .ja wsD ancl C the oscillating bracket C,

and the adjustable stop 0 as and for the purpose set forth.

' OAKLEY S. WALKER.

Witnesses:

FRED. E. KNIGHT, GEoRGE A. WARD.- 

